The long-range goal is to determine the characteristics of different speech production disorders, associated with various neurological diseases. Measurement procedures have been demonstrated to be valid for differentiating the speech production of normal aging adults from that of patients with Parkinson's disease and for measuring change in speech symptoms associated with neuropharmacological manipulation of Shy-Drager's Syndrome, Tardive Dyskinesia and Huntington's Chorea. The testing procedures include frequency and intensity calibration, a standardized testing format and normal control data for age and sex between 18 and 75 years. Acoustic analyses include spectrographic tracings of frequency and intensity changes over time; graphic sound intensity level recordings; and digital signal processing to measure pitch perturbations. Completed studies have demonstrated that (a) quantitative acoustic measures are valid for assessing degree of pathology as well as for differentiating between hypokinesic and hyperkinesic types of dysarthria; (b) that the first evidence of pathology associated with Tardive Dyskinesia is in lingual, labial and mandibular coordination during rapid speech articulation; (c) that measures of laryngeal control differentiate Shy-Drager's Syndrome from idiopathic orthostatic hypotension in the early stages of disease.